Light curing:
Since you brought up light curing putty I thought I mentioned my experience with this stuff.
Its
THE most expensive putty I've every used, but well worth the money if you're short on time or just don't like waiting X amount of time.
The Tamiya stuff cures in 1 minute under sunlight and in 2 minutes under a fluorescent light.
Notes:
1. prior to using the putty sand the area to be puttied with 400 or lower grit sandpaper (I also use my x-acto and scratch deep lines in the area). The original binding powers aren't that good on this putty so you will have to give it more to tooth on to.
2. After the puttied has cured, you will have a yellow "goop" on top of the putty, wipe that off with lacquer thinner or it will be unpaintable. It should have a yellow crusty color when 'clean'.
I mainly use this in small amounts, fixing pit holes or small areas that need to be filled. Sands very nicely.
For major body mods I would suggest polyester-putty. Easy to use, cheap, fast. The Tamiya stuff cures in around 45 minutes IIRC, automotive poly-putties have cure times from 5 minutes up to 2 hours I think.
Pros: Cheap, fast, very easy to sand and shape.
Cons: Holes (90% of the time you will have to recoat the puttied area to fill up holes made when mixing the putty), very dusty when sanded, not that rigid (if say you where making a door completely out of this, I would suggest some kind of support)
From my experience, poly-putty is best for major rough shaping, 2 part epoxy for rigid parts, light curing for small fixes. I try to stay away from 1 part putties altogether, but I do use tamiya basic when I'm lazy
HTH, Steve